"The Comprehensive Enzyme Information System" A database covering over 5000 enzymes, classified according to the Enzyme Commission (EC) that was developed and is maintained by the Institute of Biochemistry and Bioinformatics at the Technical University of Braunschweig, Germany."
"...is a free chemical structure database providing fast text and structure search access to over 28 million structures from hundreds of data sources."
"This database links over 12,000 consumer brands to health effects from Material Safety Data Sheets (MSDS) provided by manufacturers and allows scientists and consumers to research products based on chemical ingredients."
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"This site provides thermochemical, thermophysical, and ion energetics data compiled by NIST under the Standard Reference Data Program."
Provides information on the biological activities of small molecules and is organized into three linked databases: PubChem Substance, PubChem Compound, and PubChem BioAssay.
"Databases on toxicology, hazardous chemicals, environmental health, and toxic releases."